1. Field of the Invention
The present invention is in the field of semiconductor fabrication and more particularly in the field of producing small features in a semiconductor device.
2. Description of Related Art
In the field of semiconductor fabrication, an important characteristic of any fabrication process is the minimum feature size that can be produced reliably with the process. The minimum feature size dictates, to a large extent, not only the performance or speed of an integrated circuit device, but also the size of the device. The size and speed of an integrated circuit device are critical parameters. Accordingly, it is generally is desirable in any fabrication facility to be able to produce increasingly smaller features.
One traditional method of reducing feature sizes has been to replace existing photolithography equipment (commonly referred to as steppers) with next generation steppers. The obvious drawback to this approach is the enormous amount of capital required to purchase, install, and qualify a new line of steppers. Consequently, replacing existing equipment is frequently cost prohibitive and manufacturers are always interested in implementing fabrication techniques that extend the useful life of their steppers.
Another problem associated with the fabrication of small features is related to defectivity. It is well known that, as minimum geometries shrink, the number of fatal defects will increase given the same level of defects in the fabrication facility. This is especially true in the area of photolithography where the use of photoresist and photoresist processing tend to generate a relatively large number of particles. It would be desirable to implement a process in which final or post-etch dimension of a feature is reliably smaller than the printed dimension of the corresponding photolithography feature.